Adib V, Spratt D, Ng Y-L, Gulabivala K
Unit of Endodontology, Eastman Dental Institute for Oral Health Care Sciences, University College London, London, UK.
Int Endod J. 2004 Aug;37(8):542-51. doi: 10.1111/j.1365-2591.2004.00840.x.
To identify the cultivable bacterial flora in root filled teeth with persistent periapical lesions and to locate their distribution within the root canal system using an in vitro sampling protocol.
Eight freshly extracted root filled teeth were collected from the Oral and Maxillo-facial Surgery Department, Eastman Dental Hospital. Seven teeth were associated with persistent apical periodontitis and also showed evidence of coronal leakage. Teeth were transferred to an anaerobic chamber immediately after careful extraction and sectioned transversely to give a crown (in all but one case) and two root segments (coronal and apical). Two samples were obtained from each segment, one from dentine and the other from the restoration or gutta-percha (GP) root filling (46 sites in total). The samples were dispersed, serially diluted and cultured on blood agar and fastidious anaerobic agar (with 5% defibrinated horse blood). The primary growth was subcultured to obtain pure isolates, which were identified by routine microbiological techniques and commercial enzyme tests.
A total of 252 strains were isolated from all the teeth. Of all the isolates, the most prevalent bacteria were Gram-positive facultative anaerobes 189/252 (75%) with staphylococci (48/252, 19%), streptococci (44/252, 17%), enterococci (20/252, 8%) and Actinomyces species (20/252, 8%) being found in most of the teeth (6/8, 6/8, 5/8, 5/8 and 7/8, respectively). Of the obligate anaerobes (17%), peptostreptococci (7%) were also present in most teeth (7/8). A statistical association between bacterial flora and site (crown/coronal/apical) or surface (dental/GP/restoration) could not be shown.
The predominant group of bacteria in root filled teeth with persistent apical periodontitis and coronal leakage was Gram-positive facultative anaerobes of which staphylococci followed by streptococci and enterococci were the most prevalent.
采用体外采样方案，鉴定患有持续性根尖周病变的根管充填牙中的可培养细菌菌群，并确定其在根管系统内的分布情况。
从伊斯特曼牙科医院口腔颌面外科收集8颗新鲜拔除的根管充填牙。7颗牙齿伴有持续性根尖周炎，且有冠部渗漏的迹象。牙齿小心拔除后立即转移至厌氧箱，横向切片得到一个冠部（除1例以外的所有病例）和两个根段（冠部和根尖部）。从每个根段获取两个样本，一个来自牙本质，另一个来自修复体或牙胶（GP）根管充填物（共46个位点）。将样本分散、连续稀释，接种于血琼脂和苛求厌氧琼脂（含5%去纤维马血）上培养。将初代培养物进行传代培养以获得纯培养物，通过常规微生物学技术和商业酶试验进行鉴定。
从所有牙齿中共分离出252株菌株。在所有分离菌株中，最常见的细菌是革兰氏阳性兼性厌氧菌189/252（75%），其中葡萄球菌（48/252，19%）、链球菌（44/252，17%）、肠球菌（20/252，8%）和放线菌属（20/252，8%）在大多数牙齿中被发现（分别为6/8、6/8、5/8、5/8和7/8）。在专性厌氧菌（17%）中，消化链球菌（7%）也存在于大多数牙齿中（7/8）。未发现细菌菌群与位点（冠部/冠段/根尖段）或表面（牙本质/GP/修复体）之间存在统计学关联。
患有持续性根尖周炎和冠部渗漏的根管充填牙中，主要细菌菌群是革兰氏阳性兼性厌氧菌，其中葡萄球菌最为常见，其次是链球菌和肠球菌。
